It can be useful and desirable to perform mobile wireless device position determination in a wireless communications system. Accurate mobile wireless device position determination can be a difficult task particularly in an indoor environment. There may be an insufficient number of permanent fixed location anchor points from which to transmit reference signals or measured detected signals. It may be inconvenient or impractical, e.g., from a physical construction viewpoint or financial cost benefit analysis viewpoint, to install and operate a complete set of permanent fixed location anchor points in the building to provide full coverage. Some mobile device location determination approaches are based on the use a signal reference map with measured signals being matched to expected values. However, the initial signal reference map may have been based on a limited or incomplete survey and/or estimation. The survey which generated the map may have used a very limited number of actual measurements and relied on a large amount of estimation and/or interpolation. As another example, accurate signal loss parameters associated with different wall construction materials and/or different wall thicknesses used throughout a building may not be known. In addition environmental conditions may change over time, e.g., a door may be opened or closed at different times of a day, partitions may be added in an office due to remodeling, furniture may be added, removed or rearranged, different electrical equipment may be installed in the building over time, different electrical equipment may be operating at different times of the day, etc.
Based on the above discussion it should be appreciated that there is a need for improved methods and apparatus related to mobile device position determination to provide move complete and/or accurate location determination of mobile devices. At times one mobile device may be in a situation where it could provide assistance in determining the location of other mobile devices. Cooperation is particularly challenging in wireless networks where many physical resources such as power or network capacity are limited. In a cooperative positioning framework, it is beneficial if distributive approaches used for different types of joint position estimation and/or joint environment estimation are resource efficient, e.g., in terms of air link resource utilization.
In view of the above discussion, it should be appreciated that there is a need for methods and apparatus for facilitating cooperation with regard to position determination operations. It would be beneficial if such methods and/or apparatus allowed cooperation when needed without excessive overhead and/or unnecessary signaling.